The S&P 500 rose 0.28% to 1,461 in midday trading Wednesday.

The Dow Jones Industrial Average was up 0.46% to 13,390, while the Nasdaq was up 0.51% to 3,108.

The yield on a 10-year treasury bond was off 0.48% to 1.86%.

The price of gold fell 0.48% to $1,654 per ounce.

Shares of Irvine-based disk drive maker Western Digital Corp. rose about 4% to $44 for a market value of $10.6 billion. Rival Seagate Technology LLC of Cupertino raised its revenue guidance for the December quarter, sending its shares up about 5% to a market value of $12.4 billion.

Irvine-based Standard Pacific Corp. was up about 3% to $8 for a market value of $2.8 billion. Homebuilders were generally up in afternoon trading.

Huntington Beach-based BJ’s Restaurants Inc. was down about 4% to $33, after Wells Fargo & Co. lowered its rating of the restaurant operator from “outperform” to “neutral.” Restaurant companies were generally flat to down in afternoon trading Wednesday. BJ’s had a recent market value of $915 million.

Tustin-based drug developer Peregrine Pharmaceuticals shares fell back about 12% to $2, following a jump of about 30% on Monday, which came after the company said an earlier-reported discrepancy it found in the results of its lung cancer drug candidate bavituximab affected only one-milligram doses and not the three-milligram dosage. Peregrine had a recent market value of $269 million.